Offset-roller for perfecting printing-machines



J. T. HAWKINS.

TING PR OFF-SET No. 418,980 Patented Jan. 7, 1890.

UNITED STATES PATENT OFFICE.

JOHN T. I-IAIVKINS, OF TAUN TON, MASSACHUSETTS.

OFFSET-ROLLER FOR PERFECTING PRINTING-MACHINES.

SPECIFICATION forming part of Letters Patent No. 418,980, dated January'7', 1890.

Application filed March 28, 1889.

To aZZ whom it may concern:

Be it known that I, JOHN T. HAWKINS, of Taunton, in the county ofBristol and State of Massachusetts, have invented a new and usefulImprovement in Offset'Rollers for Perfecting Printing-Machines, whichinvention is fully set forth and illustrated in the followingspecification and accompanyi u g drawings.

The object of this invention is to provide an elastic roller which maybe run in contact with the freshly first-printed sides of the sheets orweb of paper or in contact with an impression-cylinder in a perfectingprintingmachine, which roller shall have an easily-renewablenon-absorbent outer covering of such character as will readily take upsuperfluous ink from the sheets or web of paper or from the surface ofthe impression-eylinder, and be capable of being cleaned by rolling orrubbing contact of an absorbent roller or wiper therewith.

The invention will first be described in detail. and then particularlyset forth in the claim.

In the accompanying drawings, Figure 1 shows a partial outside View, Fi2 a transverse section, and Fig. 3 a longitudinal section, of theroller.

In said figures the several parts are indicated by reference-numbers, asfollows:

The core 1 is made of metal in the usual Way, and the coating 2 is ofindia-rubber or any suitable elastic substance that will not shrink withage. For the non-absorbent surface the outer film or coating 3 ispreferably constituted of a mixtu re of printingink, litho graphicvarnish, and a suitable drier, thoroughly dried before being used, orany equivalent composition which will be impervious to, but readily takeink from, a printed sheet, and which can be readily cleaned by a rubbingaction. In such a case an india-rubbersurfaced roller would be permeableto or dis solved by oily substances-such as prin ting- Serial No.305,195. (No model.)

molasses, or glue and clycerine or such other compound as is generallyused for the inking form-rollers of printing-machines, which isimpermeable to printing-ink, but shrinks considerably with age, thisuniformity of surface velocity cannot be preserved if the roller bepositively driven by gearing, because of the variations in diameter ofthe shrinkable compound.

I am aware that an offset-roller composed of glue and molasses or anequivalent composition running in contact with an impression-cylinder ofa printing-machine is not new, as such is fully described in Patent No.227,157, granted Mayat, 1880, and such I do not claim; but

As of my invention I claim An offset-roller for printingmachines,composed of a central core, as 1, an elastic nonshrinltable firstcoating, as 2, and an outer renewable non-absorbent covering of acompound varnish, consisting, preferably, of printing'ink, lithographicvarnish, and a suitable drier, whereby superfluous ink adhering to saidvarnish-coveril'lg may be readily removed therefrom by an absorbentroller or Wiper, substantially as set forth.

JOHN T. HAWKINS. Witnesses:

J. F. HALEY, ALBERT J. PARK.

